Hey, that’s my seat!

The humble ant is one of the insect world's most social creatures. Like bees and termites, ants live in huge groups called colonies. Within the colony, each ants has a role to play, from defending the group or gathering food, to raising their young and caring for the egg-laying queen. Then there are the amazing feats of individual ant species.

Leafcutter ants gather leaf pieces not for eating, but as places upon which to grow the fungus they do eat. Army ant colonies attack and overwhelm much larger creatures as one giant mass. And several ant species will join tightly together to form living "rafts" to protect a colony during a flood. These rafts can stay intact and afloat not for hours, but days. And even more amazing, it seems that each ant has specific spot on the raft.

Fighting back against the flood

One of these raft species, the Alpine silver ant, is being studied by Jessica Purcell, a scientist at the University of California at Riverside. Alpine silver ants live in floodplains in Europe. Rising water levels often wash through their home. Building a raft is how they save the group.

As seen in the video at the top, Purcell colour coded some of these ants to see where they went each time a raft was built (this process is called "self-assembly"). Again and again, certain ants went to the same basic areas of the raft. Some went to the edges, others to the middle. Just as in other parts of their society, each ant had a "job" to perform. And they remembered it.

“These elaborate rafts are some of the most visually stunning examples of cooperation in ants,” Purcell said. “They are just plain cool. Although people have observed self-assemblages in the past, it’s exciting to make new strides in understanding how individuals coordinate to build these structures.”